Search PubMed⌕ Search

Biomedical subjects

T Tsuji

Publications and source records attributed to T Tsuji.

At least 1,045 records · Page 58Linked to original sources

Enzyme-linked immunosorbent assay for detection of receptors for polymerized human serum albumin on hepatitis B surface antigen particles.

An enzyme-linked immunosorbent assay (ELISA) was developed to detect the polymerized human serum albumin (pHSA) receptor on hepatitis B virus surface antigen (HBsAg) particles. The receptor values on particles from HBeAg-positive patients were significantly higher than those from anti-HBe-positive and HBeAg-, anti-HBe-negative patients. In patients' sera with moderate to high receptor values, there was significant correlation between the values obtained in the ELISA and serum DNA-polymerase activity (P less than 0.005), but not with HBeAg titer. During a 1-year follow-up of 47 HBeAg-positive patients with chronic hepatitis, termination of active viral replication, as evidenced by seroconversion from HBeAg to anti-HBe-positive, was observed in 1 of 26 with high initial receptor values, 2 of 12 with moderately high values and 6 of 9 with low receptor values. The results suggest that the ELISA described, which detects pHSA receptors on HBsAg particles, might be of value as a prognostic test in HBeAg-positive chronic hepatitis type B.

DNA-Directed DNA Polymerase↗

Structural changes of carbohydrate chains of human thyroglobulin accompanying malignant transformations of thyroid glands.

Carbohydrate moieties were released from human thyroglobulins prepared from normal and transformed, thyroid tissues by hydrazinolysis. The oligosaccharides thus prepared were fractionated by DEAE-cellulose, Bio-Gel P-4, concanavalin-A--Sepharose and Ricinus-communis-agglutinin--Sepharose columns and were characterized by exo-glycosidase and endo-glycosidase digestions, methylation analysis and 400-MHz 1H-NMR spectroscopy. These studies showed that the alterations accompanying malignancy occurred in complex-type carbohydrate chains and exhibited the following structural features: (a) a complex-type carbohydrate chain containing 1 phosphate in a diester linkage was present in all the malignant thyroglobulins. (b) Asialo-carbohydrate chains with biosynthetically incomplete structures were found in all of the malignant thyroglobulins. (c) Carbohydrate chains of higher molecular mass, which have repeating Gal-GlcNAc disaccharides and peripheral alpha-fucosyl residues were present in metastatic papillary carcinoma.

Carbohydrate Conformation↗

Interaction of human platelet membrane glycoproteins with collagen and lectins.

The binding of platelets to collagen is the first step in hemostasis. We attempted three approaches for elucidation of the chemical nature of receptors of human platelets for collagen. First, we examined the effect of platelet surface alteration by chymotrypsin treatment. On increasing the concentration of chymotrypsin, collagen-induced platelet aggregation and the release reaction decreased, an in parallel with this change, remarkable decrease of membrane glycoproteins IIb and V, as well as 400 kDa and 300 kDa membrane proteins, was observed. Secondly, effects of several lectins on the platelet-collagen interaction were examined. Lens culinaris agglutinin was found to specifically inhibit the platelet aggregation and release reaction induced by collagen. This inhibition appeared to be caused mainly by blocking of the collagen receptors on platelets by Lens culinaris agglutinin. Furthermore, Lens culinaris agglutinin was found to bind preferentially to glycoprotein IIb as identified by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis of platelet membranes followed by staining with 125I-Lens culinaris agglutinin. In addition, a polymerized preparation of Lens culinaris agglutinin induced platelet aggregation. Thirdly, the membrane component which could bind to collagen-Sepharose 4B was determined. Analysis by SDS-polyacrylamide gel electrophoresis combined with autoradiography or fluorography revealed that glycoprotein IIb was most enriched in the bound fraction to collagen. From these results, glycoprotein IIb is most likely a receptor for collagen on human platelet membranes.

Blood Platelets↗

Keratoconus with pellucid marginal corneal degeneration.

Examination of 1,625 Japanese patients with keratoconus and 20 patients with pellucid marginal corneal degeneration showed that 17 patients with pellucid degeneration also had keratoconus in the central portion of the cornea. Three patients with pellucid degeneration without keratoconus showed bilateral involvement. Among the 17 cases of pellucid degeneration with keratoconus, eight patients showed bilateral involvement and the others showed unilateral involvement. Pellucid marginal corneal degeneration with or without keratoconus may be a variant of keratoconus or a different manifestation of the same etiologic factor.

Adult↗

Simplified single radial immunodiffusion detection of albumin receptors on HBsAG particles and its significance regarding sero-changes of HBeAG in hepatitis-B patients.

A simplified single radial immunodiffusion (SRID) method to detect HBsAg particles albumin receptor activity in regard to polymerized human serum albumin (pHSA) (binding-activity of pHSA = pHSA-BA or albumin receptor activity) was developed and its significance in HBeAg-positive hepatitis B patients after a one year follow-up study was discussed. The pHSA-BA determined by the simplified SRID method was classified into 5 grades; +, +/- and -, and the results of this grading of test sera agreed well with those obtained by the ELISA quantitative assay. According to the results of one year follow-up study in sero-changes of HBeAg in 35 HBeAg-positive cases, 7 cases with pHSA-BA did not show HBeAg sero-change, but of 16 cases with pHSA-BA and 12 cases with (+) pHSA-BA 3 (18.8%) and 7 (58.3%) cases showed HBeAg sero-changes, respectively. These results suggest that the present simplified SRID detection of albumin receptor on HBsAg particles might be a useful method for the laboratory investigation of hepatitis B patients.

Adult↗

Thiopental potentiation of isolated rabbit pulmonary artery contractions with alpha receptor agonists.

The effects of thiopental sodium on the adrenergic neuroeffector junction were studied in isolated rabbit pulmonary arteries. Basal tension was not altered by thiopental (2 X 10(-5) and 10(-4) M) but was increased by high concentrations of thiopental (5 X 10(-4) M). Thiopental (10(-4) and 5 X 10(-4) M) potentiated contractions induced by transmural electrical stimulation. Contractile responses to exogenously applied low concentrations of norepinephrine (NE) were potentiated by thiopental (2 X 10(-5), 10(-4) and 5 X 10(-4) M), whereas those to high concentrations were not altered. In strips previously incubated in 1-[7,8-3H]-NE (10(-7) M), the release of [3H] induced by transmural stimulation (5 Hz) was not altered by thiopental (10(-4) and 5 X 10(-4) M). Potentiation by thiopental (10(-4) M) of the responses to transmural stimulation was not affected by prior application of cocaine or hydrocortisone. Contractions induced by alpha receptor agonists (phenylephrine and methoxamine) were potentiated by thiopental (10(-4) M), while those induced by acetylcholine were not altered. Contractile responses to potassium chloride were attenuated by thiopental (10(-4) M). Amobarbital sodium and pentobarbital sodium (10(-4) M, respectively) attenuated contractions induced by NE. It may be concluded that thiopental specifically increases the responsiveness of postsynaptic alpha receptors to NE.

Acetylcholine↗

Three-dimensional architecture of altered dermal elastic fibers in pseudoxanthoma elasticum: scanning electron microscopic studies.

The three-dimensional architecture of the altered dermal elastic fibers of patients with pseudoxanthoma elasticum has been demonstrated using a scanning electron microscope. Each of the altered elastic fibers could be divided into three parts: (i) a normal-looking, slender part which is composed of thinner fibrils, (ii) a thickened, tortuous part covered with an amorphous substance, and (iii) a markedly damaged part where calcium is exposed to the surface of the fibers. The presence of calcium and phosphorus in the altered elastic fibers has been proved by an electron x-ray microanalysis.

Calcium↗

The surface structural alterations of elastic fibers and elastotic material in solar elastosis: a scanning electron microscopic study.

The surface structure of altered elastic fibers and elastotic material in solar elastosis has been described using a scanning electron microscope. There were 3 different areas in the dermis, depending on the degree of changes in elastic fibers: areas of (1) normal-looking fibers, (2) thick, cylindrical fibers, and (3) a large mass of markedly changed fibers. They were mainly located in the deep, middle, and upper dermis, respectively. The normal-looking fibers were the same as the normal elastic fiber. The thick, cylindrical fibers showed various findings ranging from relatively normal to heavily damaged surface. The large mass was composed of a cord-like element and a fine net-like one. There was a transition between the thick, cylindrical fibers and the large mass. It is suggested that the thick, cylindrical fiber is an early event and the mass is more damaged, as one of the elastotic changes in solar elastosis. It is also suggested that the thick, cylindrical fiber corresponds to the fibrous form and the mass to the amorphous form of the elastotic material.

Aged↗

Comparison of effects of nicked and unnicked Escherichia coli heat-labile enterotoxin on Chinese hamster ovary cells.

The effect on nicking (proteolytic cleavage) of heat-labile enterotoxin (LT) on its activities on Chinese hamster ovary (CHO) cells was examined. LT nicked with trypsin induced morphological change (elongation) of CHO cells from round to spindle-shaped cells faster than did unnicked LT. The times for elongation of 50% of the CHO cells with nicked and unnicked LT were 3 and 6 h, respectively. The activity of nicked LT on CHO cells was not inhibited by antiserum 20 min after treatment, whereas that of unnicked LT was inhibited by antiserum until ca. 130 to 160 min after treatment. These data suggest that unnicked LT remains on the cell surface longer than nicked LT and thus induces morphological changes of CHO cells more slowly than does nicked LT.

Animals↗

Potentiating effect of methysergide on norepinephrine-induced constriction of the isolated internal carotid artery of the dog.

The stainless steel cannula inserting method was used to examine the effects of methysergide on 5-hydroxytryptamine (5-HT)- and norepinephrine-induced vasoconstriction in the isolated internal carotid artery of the dog. 5-HT, at a dose of 0.3 microgram, induced a marked increase in perfusion pressure, usually over 100 mm Hg. On the other hand, norepinephrine produced a relatively small increase in perfusion pressure (20-40 mm Hg) at a large dose of 10 micrograms. Methysergide inhibited 5-HT-induced vasoconstriction. Norepinephrine-induced vasoconstriction was significantly potentiated by treatment with methysergide and blocked by phentolamine. Methysergide also enhanced the vasoconstrictor response to potassium chloride. Thus, it is suggested that the potentiating effect of methysergide on norepinephrine-induced vasoconstriction may partially be due to activation of the inward calcium channel of the internal carotid artery.

Animals↗

Detection of serum blocking factors and antibodies to the albumin receptor on HBsAG particles in healthy persons and patients with liver diseases.

An enzyme-linked immunosorbent assay (ELISA) for the detection of serum blocking factors (BF), or antibodies to the albumin receptor on HBsAg particles, was developed, and its clinical usefulness was examined in healthy persons and patients with liver diseases. Thirteen of 80 anti-HBs-positive female (16.3%) had BF, but all 25 male anti-HBs-positive, 41 female and 32 male anti-HBs-negative subjects were negative for BF. The activity of BF in BF-positive cases was not associated with the positive reciprocal hemagglutination titer of anti-HBs. For a neutralization test of BF, the BFs from 5 cases were absorbed with IgG-immunobeads. It was determined that these IgG-BFs were antibodies to the albumin receptors on HBsAg particles. No significance between positive-BF and abnormal S-GPT levels was recognized. These results suggest that the present test for the detection of BF, or anti-albumin receptor antibody, different from anti-HBs, might be useful for diagnosis of hepatitis B and as a marker for HB virus.

Adult↗

Albumin receptors on HBsAG particles and subsequent sero-conversion designate HBeAG-positive patients among chronic active liver disease patients.

An enzyme-linked immunosorbent assay (ELISA) for the purpose of detecting the albumin receptor on hepatitis B virus surface antigen (HBsAg) particles was developed. Patient sera with moderate to high receptor values demonstrated significant correlations with serum DNA-polymerase activity (p less than 0.005), but not with HBeAg titer. Within one year of the study of 47 HBeAg-positive patients, only in the group of 12 patients with the moderately high values and 9 with low values, did 2 (16.7%) and 6 cases (66.7%) sero-convert, respectively. These results suggest that the albumin receptor might be a useful marker of HBsAg-positive patients.

DNA-Directed DNA Polymerase↗